They have a list of no-nos, which your application can't require (as in, need for correct operation) to run. This list includes a gyroscope, camera, WAN module, Bluetooth, microphone, GPS, or micro-SD. In addition, if your app uses Google's mobile services, like cloud to device messaging, they need to be removed "gracefully". Amazon gives us an example of graceful as "an error message such as "This feature is not currently available on this device".

There's also a notice that Google's in app billing won't be supported, but they're working on their own solution.